ORGANS AND LIVING TISSUES LEGENDEE. 419 



appearances of the tissues so preserved. In 1910 Harrison, having 

 placed fragments of an embryo frog in a drop of coagulated lymph 

 taken from an adult, saw them contmue then- development for sev- 

 eral weeks, the muscles and the epithelimn differentiating, the nervous 

 rudiments sending out into the lymph filaments similar to nerve 

 fibers (fig. 5, pis. 2, 3). Since 1910, with the aid of Dr. Minot, I have 

 succeeded in preserving alive the nerve cells of the spinal ganglia of 

 adult dogs and rabbits by placing them in defibrinated blood of the 

 same animal, through which there bubbled a current of oxygen. 

 At zero and perhaps better at 15°-20°, the structure of the cells and 

 their colorable substance is preserved without notable change for 

 at least four days; moreover, when the temperature is raised again 

 to 39°, certain of the cells give a proof of their survival by forming 

 new prolongations, often of a monstrous character. At 39° some 

 of the ganglion cells which have been preserved rapidly lose their 

 colorability and then their structure breaks up, but a certain number 

 of the others form numerous outgrowths extremely varied in appear- 

 ance. We have besides studied the influence of isotony, of agita- 

 tion, and of oxygenation, and these experiments have enabled me to 

 ascertain the best physical conditions required for the survival 

 of nervous tissue. In 1910, Burrows, employing the technique of 

 Harrison, obtained results similar to his with fragments of embryonic 

 chickens. Since 1910 Carrel and Bm-rows applied the same method 

 to what they call the ''culture" of the tissues of the adult dog and 

 rabbit; they have thus preserved and even multijDlied cells of car- 

 tilage, of the thyroid, the kidney, the bone marrow, the spleen, of 

 cancer, etc. Perhaps Carrel and his collaborators may be criticized 

 for calling "cultm-e" that which is merely a survival and for not 

 having always distinguished between the phenomena of degeneration 

 and those of real survival, but there stiU remains in their work a 

 great element of real interest. 



In conclusion, I will cite a beautiful series of experiments, conducted 

 by Magi tot in 1911, wliich give a good idea of what practical results 

 may be expected to follow from these researches. Magitot preserved 

 for 14 and even 25 days fragments of the cornea of the rabbit and was 

 able after that to successfully graft them upon the eye of another 

 animal. Soon after he applied these results to man; after an enuclea- 

 tion of the eyeball he removed the eye and preserved it in serum; 

 seven days afterwards another man having presented hhnself whose 

 cornea had been injm-ed and rendered opaque by a jet of quickUme, 

 Magitot cut an aperture in his cornea and gi-afted there a fragment 

 of the cornea wliich he had preserved, and the graft succeeded per- 

 fectly, the man having, after some time, sufficient vision to be able 

 to go about. 



